Honestly its just wasting fuel, albeit not much, but its still wasting it. You can accomplish the same braking effects without using the motor, so instead of causing unnecessary friction in the motor and burning extra fuel, you can go a little further on that tank of gas.

 

The fuel consumption point is actually the other way around (though I agree that there's not much fuel involved here.)

You waste fuel by not using engine braking. When you engine brake w/no throttle, the fuel is cut off from the injectors and no fuel is burned. The engine keeps running with no fuel to it because the wheels turn the transmission which turns the engine, instead of the other way round (when you drive normally).

When you shift into neutral, you have to burn fuel to keep the engine running because nothing else is turning it.

I still don't see why some consider engine braking to be extra wear on the engine an any real practical level. It's true that the engine turns more while braking than when idling. But I don't see how, for example, using engine braking while slowing down 200 feet is any harder on the engine than just driving 200 more feet would be. I'm just talking about 'leaving it in gear and coasting' braking assist here.

Now if you decide to say, downshift into 2nd at 40 mph and use engine braking to slow down routinely, that might be a different story.

 

This is just a personal experience...

I have a 2002 Hyundai Accent L 5sp. It was purchased for me used in 2003, with 27,000 mi on it. I learned to drive in this car when I was 15. My dad is a semi truck driver, so he taught me all the in's and out's of driving stick.

I ALWAYS use the engine braking method described in this thread. I do it to save fuel, brake pad wear, and because I feel as though I have more control of the car, especially in winter. Typically, I do it going 40+ mph and am in 4th or 5th. Drop down to 3rd, then to 2nd.

I still have this car. I am now 20 years old. The car is 6 years old, going on 75,000 mi. Since I have owned it, I have NOT had to replace the brake pads. Incidentally, they started squeaking the other day, after taking the car to Meineke, the tech said they were fine, just a little dirty. After asking them if they looked like they needed to be replaced soon, he said no.

Also, no engine, transmission, or clutch work has had to done.

Just an FYI, I also do it in my Fit Sport AT. No probs yet, but I've only had it for 7 months.

 

How bout neither? I use engine braking only when going downhill (it saves gas)

As mentioned in my "P&G final update" thread, time your cars speed so when it will almost stop at the next stop.

About trannys being more expensive than brakes. Transmissions also last longer. And as for the engine, the engine is a machine that works better when hot. Your engine might be more efficient (faster and better mpg) if you keep the revs high.

 

When slowing down to a stop, I keep 'er in gear until ~1000rpm, then clutch in. Coasting in neutral wastes gas on a manual. As far as automatics go, I have no idea, automatics work on magic and fairy dust for all I know, so shifting to neutral down hills may actually save fuel.

 

Thanks, everyone, for their interesting and informative responses to this question. I suppose I'll have to change my one bad driving habit- holding the clutch in too much.

 

that is the theory for folks that dont know how to rev match a MT.

down shift to the lower gear and coast in gear until you come to
the point the fuel injectors turns on again. you will feel a slight push
(feels like a bump) from the engine. i clutch-in a split second before
the ecu does that and roll to a stop.

for maximum braking, i usually downshift 2 gears while revmatching
(heel and toe).

 

Yes, I think we can pretty much all agree on that. Holding the clutch in too much isn't a good thing. Once you've picked a gear (including neutral), let the clutch back out.

 

+1 manhout.

From what I've gathered idle runs about .25 to .3 gph (these numbers I believe Paul pulled off his SGii). Typical nICE coast time (or DFCO in gear) is what 2 minutes? On my commute I've got a total of 10 minutes of nICE-on. To utilize DFCO when coming to a distant red-light or whatever I will loose approximately 30% of distance traveled due to gear drag.

So the calc is:

10 minutes nICE-on = .041 gals x $3.80/gal (at .25 gph at idle) or $0.16/day cost.

This is v.s. 40mpg @ 60miles/hour x 10 minutes = 0.25gals x $3.80/gal = $0.95. This equals $0.79/day savings using nICE-on. (or in my case save $197.5/year )

DFCO = 0 gals = Free + 30% distance at 40mpg at 60mph x 3 minutes = ..075 gals x $3.8/gal = $0.28/day cost.

Now this isn't an apples to apples comparison though as with DFCO I would have to stop/slow down anyway...nICE-on I don't. If on a long hill w/no breaking I (now) always use nICE-on as I can travel further. My feelings is that on a long commute it is a wash

Will this make you rich over the life of the vehicle? Nope. But it will buy you a nice night out! Will you have satisfaction your doing everything you can to boost your MPG and thus sticking it to OPEC? Yup!